US 5,294,754 AGranted

Direct write EC single metal layer

AssigneeIternational Business Machines Corporation

InventorLeon L. Wu

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Abstract

A direct write and laser delete system for making engineering changes in which top surface metal C4 pads each has a small satellite pad connected to it by a short connecting line that is deleted if an engineering change is to be made. Vias connect the satellite pads to a "personality" wiring layer in the module. A top surface grid of line segments allows any C4 pad to be connected to a point outside the chip boundary by means of one or more short direct write lines. There is one global X and Y engineering change grid on respective X and Y thin-film layers and another global X and Y engineering change grid on respective X and Y multi-layer ceramic module layers. All of these varied patterns are connected to lines with each chip pitch boundary where direct write connections can be made, and a grid line can be interrupted by a laser deletion of a top surface metal line.

Claims5

Dependent claims

An engineering change network for a multi-chip, multi-layer module, comprising in combination:

a top surface metal layer including plurality of C4 pads for connecting a chip to said multi-chip module and a satellite pad located adjacent each of said plurality of C4 pads and connected to a C4 pad by a short deleteable line segment;
said top surface metal layer including a plurality of interrupted line segments arranged in rows and columns so that at least one of said interrupted line segments passes in close proximity to each C4 pad of said plurality of C4 pads, said row and columns of said interrupted line segments extending beyond a chip boundary and terminating within a chip pitch boundary;
a global engineering change wiring pattern comprised of parallel X directed interrupted segments on a buried layer in said multi-layer module connected to top surface metal X direction global segments that connect said interrupted segments, said top surface metal X direction global segments disposed between said chip boundary and said chip pitch boundary;
and
a global engineering change wiring pattern comprised of parallel Y directed interrupted segments on a buried layer in said multi-layer module connected to top surface metal Y direction global segments that connect said interrupted segments, said top surface metal Y direction global segments disposed between said chip boundary and said chip pitch boundary.

2 more elements

An engineering change network for a multi-chip, multi-layer module, comprising in combination:

a top surface metal layer including plurality of C4 pads for connecting a chip to said multi-chip module and a satellite pad located adjacent each of said plurality of C4 pads and connected to a C4 pad by a short deleteable line segment;
said top surface metal layer including a plurality of interrupted line segments arranged in rows and columns so that at least one of said interrupted line segments passes in close proximity to each C4 pad of said plurality of C4 pads, said row and columns of said interrupted line segments extending beyond a chip boundary and terminating within a chip pitch boundary;
a first global engineering change wiring pattern comprised of parallel X directed interrupted segments on a first buried layer in said multi-layer module connected to top surface metal X direction global segments that connect said interrupted segments, said top surface metal X direction global segments disposed between said chip boundary and said chip pitch boundary;
a second global engineering change wiring pattern comprised of parallel Y directed interrupted segments on a second buried layer in said multi-layer module connected to top surface metal Y direction global segments that connect said interrupted segments, said top surface metal Y direction global segments disposed between said chip boundary and said chip pitch boundary;
a third global engineering change wiring pattern comprised of parallel X directed interrupted segments on a third buried layer in said multi-layer module connected to top surface metal X direction global segments that connect said interrupted segments, said top surface metal X direction global segments disposed between said chip boundary and said chip pitch boundary;
and
a fourth global engineering change wiring pattern comprised of parallel Y directed interrupted segments on a fourth buried layer in said multi-layer module connected to top surface metal Y direction global segments that connect said interrupted segments, said top surface metal Y direction global segments disposed between said chip boundary and said chip pitch boundary.

4 more elements

Dependencies are inferred from the claim text.